The present invention relates to communication networks and more particularly to a method for permitting two partner nodes to dynamically establish a transmission group number for identifying a link between the two nodes.
For purposes of the following description, a communications network can be defined as a collection of network nodes which are interconnected through communications links. A network node can be characterized as a data processing system that provides certain functions within the network, such as routing of messages between itself and its adjacent or neighboring nodes, selection of routes for messages to be transmitted between a network node and a directly-connected end node and the furnishing of directory services to end nodes. The links between nodes may be permanent communications links, such as conventional cable connections, or links that are enabled only when needed, such as dial-up telephone connections.
In establishing a connection between any two nodes, it is necessary that the link between the two nodes be assigned an identifier unique within the entire network. Conventionally, a link is identified by combining network-qualified names for the two nodes with a number assigned to a transmission group connecting the two nodes. A network-qualified node name is a name which is known to be unique in the network. Network-qualified node names are assigned when the system is initially defined or when a node is added to a previously-defined network.
Since the node names are unique within the network, a given link between two nodes is unambiguously identified for each different transmission group number applied to a link between the two nodes. Ambiguity would be created if the same transmission group number were to be applied to two or more parallel links connecting the nodes.
According to the prior art, a transmission group number is assigned to each link between two partner nodes when the system is initially defined or when one or both of the nodes or the link is added to the network.
The requirement that transmission group numbers be assigned at the time of system definition or system reconfiguration adds to the cost and complexity of network operation.